The invention relates to a closing member, and particularly to a closing member of a slide gate for a molten metal container, the closing member having at least one flow channel and being mounted for interchangeability or by way of an adjustable carrier frame.
Slide gate closing members are usually plate-shaped and have one flow channel each, and when the plate-shaped closing member is in an open position, its flow channel aligns with a flow channel of a bottom plate fastened fixedly to the bottom of the molten metal container. The upper inlet edge of the closing member flow channel wears relatively rapidly due to the thermal, erosive, and corrosive effect of the molten metal stream, especially when the closing member is moved between a control and/or a closing position and a flow position. Therefore, the entire closing member has to be replaced after a few pourings. It has already been proposed that the closing member be used bilaterally, i.e. that the working surface of the closing member that is turned upward and is worn be turned downward, so that the same flow channel is used a second time with a non-eroded working surface turned upward. However, this provides only a limited advantage with respect to the service life of the closing member because the flow channel may have also become worn at other than the upper control and closing edge of the flow channel due to the molten metal passing through the flow channel. The same also applies to the bottom plate even though the opening therein does not become eroded as quickly as that of the closing member because the latter provides the control and closing functions.
Also known is a so-called rotary slide valve which has a plate-shaped closing member with openings formed therein forming multiple (e.g. three) parallel flow channels, some of which also have different cross-sections, which open through the upper working surface and the bottom surface of the rotary closing member. The flow channels can be selectively brought into operative position by rotating the closing member about an axis perpendicular thereto. Such a closing member, however, is, by necessity, relatively large since sufficiently large closing regions must be disposed between the individual flow channels.
Also known is a sector-shaped closing member plate. Such a closing member plate is mounted to swivel about a swivel axis and has two parallel flow channels which open through the upper working surface and the bottom surface of the closing member plate. The requisite closing surface regions are, with respect to the swivel axis, spaced inwardly from the flow channels. Thus, such a closing member plate must also be relatively large. Also, it is necessary to have both a drive for swivelling the closing member plate and for causing linear motion of the closing member plate.